This invention relates to a heat-resistant overwrap film, more particularly, to an overwrap film that is improved not only in heat resistance but also in flexibility and tackiness as well.
Overwrap films are currently used as wrappers of foods under storage or cooking. Conventional overwrap films are made of thin films of polyvinyl chloride or polyvinylidene chloride, which are capable of withstanding heat at temperatures of about 140.degree. C.
As the use of overwrap films has expanded recently, a demand has arisen for products that can withstand use at even higher temperatures, namely, those which have higher heat resistance. Polymers based on 4-methyl-l-pentene melt at 220.degree.-240.degree. C. and are known to exhibit high heat resistance. Hence, it is expected that overwrap films having high transparency and heat resistance can be produced by shaping 4-methyl-l-pentene based polymers into films. However, films of 4-methyl-l-pentene based polymers have been unsatisfactory not only in flexibility but also in tackiness which is an important property in the case where they are to be used as wrappers.